The invention relates to the field of Josephson junction (JJ) devices, and in particular to a superconducting MgB2 Josephson junction (JJ) device having a buffered Si substrate comprising of MgO and AlB2 structure compounds.
Magnesium diboride (MgB2) has attracted extensive studies to fabricate Josephson junctions and circuits that can function between 20-25K using cryocoolers. The goal was to replace the Nb junction technology which requires cooling at liquid helium temperatures. MgB2 Josephson junctions have been fabricated by point contact, ramp type, and various planar structures.
Trilayer Josephson tunnel junctions using AlOx or AlN as a thin tunnel barrier layer have also been reported. However, the properties of the barrier layer and the MgB2/barrier interface in many of these junctions are not ideal because they are not well understood or difficult to control.